A fastener for fastening an elongate object to a support structure, the fastener comprising a body portion formed entirely of one or more electrically non-conductive materials and comprising a bridge, a first column extending substantially perpendicularly from a first end of the bridge and a second column extending substantially perpendicularly from a second end of the bridge, the bridge and columns together forming a U-shaped receptacle for engaging the elongate object, and a nail formed entirely of one or more electrically non-conductive materials and partially contained within the first column of the body portion for positively engaging with the support structure upon the application of force by a driving mechanism thereby fastening the elongate object to the support structure.